Ozone is an unstable gas with a half-life of less than one hour at room temperature. Ozone is a powerful oxidizer. It is a known bactericide and viricide. Methods for converting oxygen to ozone involve high-voltage corona discharge or ultraviolet light. Ozone generators making use of such methods are available for industrial uses.
Ozone has a variety of industrial applications. Applications include deodorizing air, purifying water and sterilizing medical instruments, among others. Ozone and conventional medical ozone generators are being used therapeutically in many countries and have been so for several years. Such applications include, but are not limited to, autohemotherapy, rectal insufflations, intradiscal injection, injection into knee and shoulder joints, and full body exposure.
For example, ozone is used to treat diffuse bulging or contained herniation of the spinal disc. Spinal discs are composed of a fibrous outer ring made of Type I collagen and a softer more flexible nucleus made of Type II collagen, proteoglycans and water. Patients with disc bulging or herniation suffer from pain caused by disc compression of the neurological elements, including the spinal cord, cauda equina and nerve roots. Intradiscal ozone treatment involves direct injection of a gaseous mixture of oxygen and ozone into the nucleus of the disc. Ozone releases water from the proteoglycans, reducing disc size and relieving compression of neurological elements. Some investigators believe that ozone stimulates anti-inflammatory mediators and initiates a healing response.
The mechanism of action and reported success rates of ozone treatment for spinal disc herniation are comparable to that of the enzyme chymopapain. Chymopapain was first FDA-approved in 1983 and was widely used with a success rate of 65-85%. A small number of serious complications, including death and paralysis, caused the product to lose favor in the U.S. market.
Ozone and chymopapain are two means of performing a chemical discectomy through a needle puncture. This minimally invasive approach may be preferred to surgical discectomy, which requires general anesthesia and direct access to the spinal disc.
Therapeutic ozone must be delivered shortly after being produced from oxygen. Conventional medical ozone generators pass medical grade oxygen through an electric field or ultraviolet light. This process converts an amount of oxygen into ozone. Typically, a syringe is interfaced with the generator and ozone is withdrawn from a gas chamber of the generator into the syringe for subsequent injection therapy. Often, a spinal needle is already positioned within a patient and then the syringe is placed in fluid communication with the needle for injection.
The preferred concentration of ozone for intradiscal injection is approximately 6%. The concentration of ozone is important for medical uses. If the concentration is too low, the treatment will not be effective. If the concentration of ozone is too high, detrimental effects may follow.
As such, medical ozone generators include a means for measuring the concentration of ozone. Conventional ozone generators also have means for controlling the concentration and delivery of ozone gas. For example, some generators include components that neutralize excess ozone. Other generators continuously vent ozone.
Conventional ozone generators typically include permanent and reusable electrodes. The gas chambers of conventional generators are often permanent and reusable as well. Reusable electrodes tend to degrade over time. Sterility is an issue for present ozone generators that pass oxygen through permanent and reusable gas chambers. The bioburden of these machines is unknown. Thus, the ability of ozone to sterilize these components cannot be validated. To address such, medical professionals have been known to inject the gas through a bacterial filter but compliance with this practice is sporadic as filters may not be available or the clinician may be trying to minimize equipment cost.